This invention is directed to a DC motor control circuit, and in particular, to a control circuit for effecting improved starting and stopping of the DC motor.
Heretofore, the use of DC motors for rotation at constant speeds has presented no problem. However, the starting and stopping of such constant rotation DC motors has been less than completely satisfactory when same are to be started in response to a low-magnitude voltage, wherein constant rotational speed is required immediately after starting. Such uses are voiceactuated instruments wherein a faint voice signal is required to effect a driving of a DC motor at a constant rotational speed immediately upon starting is one such type of use. Additionally, scenery cameras, printer instruments, automatic control instruments and the like, all require a high-performance, stable-operating constant rotational speed DC motor. Accordingly, a DC motor control circuit wherein improved starting and stopping is provided, and wherein the rotational speed of the rotor can be maintained constant regardless of changes in load, ambient temperature and the DC supply voltage is desired.